<?php

/**
 * Class ECICharset
 *
 * @created      21.01.2021
 *
 * @author       ZXing Authors
 * @author       smiley <smiley@chillerlan.net>
 * @copyright    2021 smiley
 * @license      Apache-2.0
 */
declare(strict_types=1);

namespace zxf\QrCode\Common;

use zxf\QrCode\QRCodeException;

use function sprintf;

/**
 * ISO/IEC 18004:2000 - 8.4.1 Extended Channel Interpretation (ECI) Mode
 */
final class ECICharset
{
    public const CP437 = 0;  // Code page 437, DOS Latin US

    public const ISO_IEC_8859_1_GLI = 1;  // GLI encoding with characters 0 to 127 identical to ISO/IEC 646 and characters 128 to 255 identical to ISO 8859-1

    public const CP437_WO_GLI = 2;  // An equivalent code table to CP437, without the return-to-GLI 0 logic

    public const ISO_IEC_8859_1 = 3;  // Latin-1 (Default)

    public const ISO_IEC_8859_2 = 4;  // Latin-2

    public const ISO_IEC_8859_3 = 5;  // Latin-3

    public const ISO_IEC_8859_4 = 6;  // Latin-4

    public const ISO_IEC_8859_5 = 7;  // Latin/Cyrillic

    public const ISO_IEC_8859_6 = 8;  // Latin/Arabic

    public const ISO_IEC_8859_7 = 9;  // Latin/Greek

    public const ISO_IEC_8859_8 = 10; // Latin/Hebrew

    public const ISO_IEC_8859_9 = 11; // Latin-5

    public const ISO_IEC_8859_10 = 12; // Latin-6

    public const ISO_IEC_8859_11 = 13; // Latin/Thai

    // 14 reserved
    public const ISO_IEC_8859_13 = 15; // Latin-7 (Baltic Rim)

    public const ISO_IEC_8859_14 = 16; // Latin-8 (Celtic)

    public const ISO_IEC_8859_15 = 17; // Latin-9

    public const ISO_IEC_8859_16 = 18; // Latin-10

    // 19 reserved
    public const SHIFT_JIS = 20; // JIS X 0208 Annex 1 + JIS X 0201

    public const WINDOWS_1250_LATIN_2 = 21; // Superset of Latin-2, Central Europe

    public const WINDOWS_1251_CYRILLIC = 22; // Latin/Cyrillic

    public const WINDOWS_1252_LATIN_1 = 23; // Superset of Latin-1

    public const WINDOWS_1256_ARABIC = 24;

    public const ISO_IEC_10646_UCS_2 = 25; // High order byte first (UTF-16BE)

    public const ISO_IEC_10646_UTF_8 = 26; // UTF-8

    public const ISO_IEC_646_1991 = 27; // International Reference Version of ISO 7-bit coded character set (US-ASCII)

    public const BIG5 = 28; // Big 5 (Taiwan) Chinese Character Set

    public const GB18030 = 29; // GB (PRC) Chinese Character Set

    public const EUC_KR = 30; // Korean Character Set

    /**
     * map of charset id -> name
     *
     * @see \mb_list_encodings()
     */
    public const MB_ENCODINGS = [
        self::CP437 => null,
        self::ISO_IEC_8859_1_GLI => null,
        self::CP437_WO_GLI => null,
        self::ISO_IEC_8859_1 => 'ISO-8859-1',
        self::ISO_IEC_8859_2 => 'ISO-8859-2',
        self::ISO_IEC_8859_3 => 'ISO-8859-3',
        self::ISO_IEC_8859_4 => 'ISO-8859-4',
        self::ISO_IEC_8859_5 => 'ISO-8859-5',
        self::ISO_IEC_8859_6 => 'ISO-8859-6',
        self::ISO_IEC_8859_7 => 'ISO-8859-7',
        self::ISO_IEC_8859_8 => 'ISO-8859-8',
        self::ISO_IEC_8859_9 => 'ISO-8859-9',
        self::ISO_IEC_8859_10 => 'ISO-8859-10',
        self::ISO_IEC_8859_11 => null,
        self::ISO_IEC_8859_13 => 'ISO-8859-13',
        self::ISO_IEC_8859_14 => 'ISO-8859-14',
        self::ISO_IEC_8859_15 => 'ISO-8859-15',
        self::ISO_IEC_8859_16 => 'ISO-8859-16',
        self::SHIFT_JIS => 'SJIS',
        self::WINDOWS_1250_LATIN_2 => null, // @see https://www.php.net/manual/en/function.mb-convert-encoding.php#112547
        self::WINDOWS_1251_CYRILLIC => 'Windows-1251',
        self::WINDOWS_1252_LATIN_1 => 'Windows-1252',
        self::WINDOWS_1256_ARABIC => null, // @see https://stackoverflow.com/a/8592995
        self::ISO_IEC_10646_UCS_2 => 'UTF-16BE',
        self::ISO_IEC_10646_UTF_8 => 'UTF-8',
        self::ISO_IEC_646_1991 => 'ASCII',
        self::BIG5 => 'BIG-5',
        self::GB18030 => 'GB18030',
        self::EUC_KR => 'EUC-KR',
    ];

    /**
     * The current ECI character set ID
     */
    private int $charsetID;

    /**
     * @throws \zxf\QrCode\QRCodeException
     */
    public function __construct(int $charsetID)
    {

        if ($charsetID < 0 || $charsetID > 999999) {
            throw new QRCodeException(sprintf('invalid charset id: "%s"', $charsetID));
        }

        $this->charsetID = $charsetID;
    }

    /**
     * Returns the current character set ID
     */
    public function getID(): int
    {
        return $this->charsetID;
    }

    /**
     * Returns the name of the current character set or null if no name is available
     *
     * @see \mb_convert_encoding()
     * @see \iconv()
     */
    public function getName(): ?string
    {
        return self::MB_ENCODINGS[$this->charsetID] ?? null;
    }
}
